David stewart



gaitei titties:

. IMPROVEMENT-" IN: 'THl-J- MANUFAGTUBE OF IRON;

T0 ALL wHoM-n' MAY CONCERN":

Beit known that I, DAvI D' STEWART, of Kittanning, in'the county of Armstrongand'state of Pennsyl mnia,a.-

have inventedanew and usefal Improvement in the hflanufacture-of: Iron and-I do hereby declare *the fo'llow ing to be a full, clear, andexact description thereof. 7 I My inventiou consists "in an-improv'edmethodj of treating iron as it;comes from' the blast-fnrnace,'o'ri remelted pig-iron, to re'movetherefromthe carbon, silicn,-sulphur, phosphorus, and otheriimpnr ities which are found in the iron, and which are not removed-from or havebeen contracted byi'the iron 'byithe zproeessof reduction from the ore.

- It is well known that pig-iron, or iron fromthe blast-furnace, contains a'largeamountofcarhon, whichit' receives in the process of reduction, and which mus't'be more or less completely removed-in order-to produce. wrought iron or steel. Carbon has a great aifinity for oxygen, greaterthan either carbon Orr-oxygen havezfor iron, and as the;union of" carbon and oxygen at a'sufiicient temperature toproduce combustion, evolves ai -great amount of heat, it follows that hy mi-xing oxygen with molten' pig -iron, the carbon ignites with vivid combustion, and is thereby eliminated, while the increase of heat thereby obtained renders the iron more-fluid,ian d obviates the necessity of using other. fuelor fire-than is furnishdby the-carbon containedin the molten iron.

The most approved mode of accomplishing this-object, heretofore introdu'ced'into-practice, isto'ponrthe melted metal from the blast-furnace into: a 'receiveror vessel through'which a stream of atmospheric air is forced' at snfficient pressure; This, known as the-pneumatic process, -is attended with-the useofveryexpensive apparatusand machinery, and, 'moreover, requires to be closely watched, as the operation, ifcontinued too long,

injures the metal; besides, it is not efi'ectualin removing the impurities other than carbon, such asrsilicon, s ulphur, phosphorus, &cl; and even .as'respects the" removal of the carbon its-operation is not always 'satisface tory', as 'it is difiicult to'secure the equal-action of the oxygen' on alllthepnrticles of ironin the receiver. My improvement produces a. much more satisfactory result, with little or no' special apparatus,v and. produces immediately-from the moltenpig-metal wrought iron, which may heat once taken to the rolls and worked'in like manner as iron which has'been puddl'ed. and squeezed. H I My improvement consists'in subjecting molten pig-,me'talor iron direct from the blast-furnaeeto the action of oxygen, (in'any convenient shape, as atmosphericair, ozone,- or othervapor or g as contriining. oir ygjem) Qtypassing the molten metal in a stream or'shower, eitherponredior.forced upwards :or. sideways, so as tosecure. .an intimate admixture of the particles-ofironwith the oxygen, orother oxygen-bearing'gasor. vapor. Iaorderf to carry this-into effect, no special apparatus is required; indeed, each manufacturer wilhprobahlyjvary the arrangement'of his furnace to suit the mode of accomplishing the desired 'resultjwhich' willbestsuit'hiscon venience or'the're'quireme'nts'of his-business.. I 4 l I v In order to enable others skilled in the'art tocarry myinve'ntion' into practical operation,-I will proceetl*to describe'one'of' the modesin which I- propose toefiectuate-mypurpose; I

Themelte'd iron may he run directly out'o f th'e-tap-hole of th'e bla st' furnacmor maybe first ponred qnt into a pot.- It is then allowed torun from an elevationtoi thirty feet, more oi"less,',to'the ground', and*byrthis;

means the ironis brought into intimate contact with the air, 'sothat-the' carbon isirapidly ignited, increasing the temperature of the m'et'allanditsflu-idity, and, at the-same tim'e; carrying'ofl"in"a great;measure tlieother impurities, such as silicon, sul'phur,'.and phosphorus, whichalso ignitewith' th'ecarbon and ar'efihh'seliminated. t Ifflit is-desired to prevent the metal becoming sp'attered-around as'it falls, when itreachesithe-ground, itmaybe poured through a pipe, cylinder, or tube, openat both ends' soas to permitth'e iree:passage. oith'eai'r' up-wardsthrough'the cylinder, This plan has the-advantage of' securing.- a more uniform' current'of air,gwhicli..

will-flow upwards through the cylinder, in consequence-of the r'arefaction caused the.heatmftheimetali A; stream o'r"cur-rent'-,of atmospheric air, either hot or cold or of ozoneporjsteam, or a'uiixture ofiany of. theses: 0r vapors,'singly' or combined,.mn.y'he introduced into the cylinder, pipe,vor. tube: through which themetal ls poured; and-,ifdesired, pressure may be applied s'oas-to create a stronger current or blast-up. through-the cylinder. if it-is'desired to add'anyfluxes t'c-the-iron,-(or physic it,-as the iroir worlrers'term:it,)ithis mayj be:- done'before the iron is pouredout; Thelieight-from' whichthewmetalis caused st'o fall may'beivariedlaccording to the'quality oithe meta1,.andalso; somewhat according to its quantity, as the' more impure the iron-,th'o

greater the height from which it should fall, the consequent distance through which it should be exposed to the action of the air or other oxygen-bearing gas or vapor, and the larger the quantity, the greater the'height should be so as to secure the more completeaction on the particles of iron." A more complete separation of the'particles of metal may be secured by pouring it through holes or perforations in a plate or otherwise! Insteadof pouring the metal downwards, the same result would be produced by an upward jet; but thevplan above indicated, it is believed, will be found the best and simplest in practice. 7

By the means above described,.of pouring molten pig-metalthrough a cylinder thirty feet high, I have produced iron which, when heated and passed through the -squeezers, gave out no cinder,thus showing that the silica had been nearly, if not entirely, removed, and from which, in the condition in which it passed from the muck-bar rolls, it was ready to be worked for any desired purpose. So that bymy process, wrought iron ready for the rolls is produced directlyfrom pig-iron. by a process requiring little or no machinery or apparatus, and

scarcely anytime,'and dispensing with theordinary troublesome and tedious processes.

I also apply the above mode of purifying iron to the manufacture of semi-steel and steel, the process being the same, tbougha more perfect and longer-continued admixture of air or other oxygen-bearing gas may be required therefor; and such application I-include in my invention.

i I do not claim the use of steam in the process above described.

Having thus described my improvement, what I claim as my invention, and desire to secure by Letters Patent, isi Iurifyin'g pig-iron orblast-furnace metal from its carbon and other impurities by passing it in a stream through ozone, atmospheric air, or other oxygen-bearing gas or vapor, substantially as and for the purposes sereinbefore described.

In testimony whereof, I, the said DAVID STEWART, have hereunto set my hand. DAVID STEWART.

Witnesses:

W. BAKEWELL,

' ELI Tonnsnos. 

